Fueling environments, such as commercial or fleet fueling stations, convenience stores, retail fueling stations, and large consumer retailers, typically include one or multiple fluid dispensers. Such fluid dispensers are most often fuel dispensers, operated by the consumer to dispense fuel (e.g., gasoline, biofuels, diesel) into a variety of vehicles. The exemplary fueling environments, however, often include other types of fluid dispensers that consumers require to maintain their vehicles. For example, fueling environments often include dispensers for water and air in order for consumers to maintain the coolant and tire systems, respectively, on their vehicles. In certain types of vehicles, such as vehicles designed to operate on diesel fuel or biodiesel, additional fluids may be required to properly operate and maintain the vehicles. For example, a diesel-powered vehicle may typically require additional fluids to provide for acceptable and lawful operation of an emissions system of the vehicles.
Selective Catalytic Reduction (SCR) is an emissions system typically used in diesel vehicles to reduce NOx emissions. In an SCR system, aqueous urea may be sprayed directly into the vehicle exhaust stream, creating ammonia gas. Through a catalytic converter, the ammonia combines with the NOx gasses to convert such gases into nitrogen and water. This emissions solution has been employed in Europe for several years, where the aqueous urea solution is often referred to as “AdBlue.” In some instances, use of SCR systems may be dictated by regulatory requirements, such as government emission standards designed to limit an amount of emissions acceptably expelled from a diesel vehicle.
SCR systems in the United States typically employ Diesel Exhaust Fluid (DEF), which is often used as a generic name for the aqueous urea solution. In some vehicles, such as, for example, diesel trucks, a separate DEF storage tank may be maintained on the truck and must be refilled regularly. For a variety of reasons, including convenience, fueling environments may include both fuel dispensers and DEF dispensers on the premises. DEF dispensers are often designed to account for the chemical characteristics of the aqueous urea solution (DEF). Further, since DEF is typically a 32.5% solution of chemically pure urea in deionized water, its freezing point is approximately 12° F. (−11° C.). Various components of the DEF dispenser may therefore be more easily susceptible to damage from freezing conditions.
Several solutions to the challenge of maintaining DEF dispensers in environmentally-challenging climates have been employed. For instance, some solutions include merely enclosing the DEF dispenser components in a housing with a simple hinged door allowing access to such components. Such solutions, however, often suffer from several disadvantages, including the possibility of significant abuse and damage to the door in fueling environments. Further, there is no assurance the door will be closed after use, negating any climate-control effects of the DEF dispenser housing. Another solution includes the use of electrically-operated automatic doors allowing access to the components of the DEF dispenser. While such doors may solve the problem of accidental non-closure, they often have operational problems in fueling environments that are often abusive to equipment. Yet another solution includes completely enclosing the DEF dispenser components within an enclosure, allowing only certain components, for example a dispensing nozzle and hose, to be removed from the enclosure. Such a solution often requires constant tension to be placed on the hose, urging it back into the enclosure. Thus, a fueling consumer must always wrestle with the hose under tension and there could be problems drawing hose accessories, for instance a breakaway, into the cabinet. Another solution includes a dispenser housing with multiple openings, allowing access to the nozzle and hose, respectively. The hose opening, however, is usually protected by interlocking brushes, which may help keep heat within the enclosure while allowing the hose to pass through the opening. Such a design, however, does not totally seal the enclosure against the loss of thermal energy to the environment. Further, the brushes often hamper a user as she attempts to extend the hose from the cabinet.